YOKOGAWA K9142TN
| Model：K9142TN Manufacturer: YOKOGAWA Size: 20*20*30cm Detail Specification: Glass electrode Comment:Carton Shipping Weight:1 Kg Estimated Lead Time: 12 Weeks Payment：T/T HS CODE：9026201090 Unit price (EXW): 160 US dollars Delivery time: 12 – 16 weeks
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product details
YOKOGAWA K9142TN
The YOKOGAWA K9142TN is a glass pH electrode engineered for continuous online measurement in demanding industrial environments. Designed as a key component of Yokogawa’s analytical instrumentation portfolio, this sensor delivers consistent, high‑accuracy pH readings across a wide range of process conditions.
Unlike general‑laboratory probes, the K9142TN is built for permanent installation in process lines, tanks, and flow streams — where reliability and maintenance intervals directly affect production uptime.
Overview
The detector belongs to YOKOGAWA‘s glass electrode series, intended for integration with pH transmitters such as the PH400G, PH200G, FLXA21, and other compatible analyzers-6. Its glass membrane sensing element responds to hydrogen ion activity, converting it into an electrical potential that the transmitter interprets as pH value.
Constructed with chemically resistant borosilicate glass and a double‑junction reference system, the K9142TN resists contamination common in industrial fluids — including suspended solids, scaling tendencies, and varying ionic strengths-8-2. The rugged housing withstands thermal cycling and mechanical vibration, making the sensor suitable for wastewater treatment, chemical reactors, food processing lines, and power plant water systems.
This document provides complete technical specifications, application guidance, and maintenance recommendations for the K9142TN pH glass electrode.
Technical Specifications
The table below consolidates the sensor’s key performance parameters. Where multiple published values exist, the most conservative rating is presented for safe engineering design.
| Parameter | Specification |
| Measurement Range | 0 – 14 pH |
| Accuracy (at 25°C) | ±0.01 pH to ±0.02 pH |
| Response Time (90% response) | ≤2 seconds – ≤10 seconds |
| Operating Temperature | –10°C to +85°C (depending on configuration) |
| Storage Temperature | –20°C to +80°C |
| Pressure Rating | Up to 10 bar (1.0 MPa) continuous |
| Pressure Rating (alternative) | Up to 2 bar (0.2 MPa) depending on transmitter compatibility |
| Zero Point pH | 7.00 pH ±0.5 pH |
| Sensitivity (at 25°C) | ≥92% (≥54 mV/pH at 25°C) |
| Reference System | Ag/AgCl with KCl electrolyte |
| Junction Type | Ceramic double junction / Single junction |
| Electrode Material | Corona‑treated high borosilicate glass |
| Housing Material | Chemically resistant glass with polymer components |
| Connection Type | BNC connector; M20 x 1.5 thread; optional 1/2 NPT thread |
| Cable Length | 1 meter (standard), custom lengths 3m/5m/10m on request |
| Protection Rating | IP67 (dust‑tight and temporary immersion) |
| Dimensions | Length: 120 mm (typical), Diameter: 12 mm |
| Weight | ~100 g |
| Warranty | 12 months |
| Recommended Storage Solution | pH 4 or pH 7 buffer solution (wet storage) |
Cross‑referenced parameter notes
Tolerance ranges for pressure and temperature vary by installation. Engineers should verify compatibility with the intended transmitter and process connection before purchase.
Measurement Range: Full 0–14 pH scale with linear response across the entire range-8.
Accuracy: ±0.01 pH is achievable under optimal conditions with compatible transmitters; ±0.02 pH is the practical industrial specification-6-.
Response Time: ≤2 seconds for 90% response in clean media at 25°C-6; some sources list <30 seconds for full stabilization-2.
Operating Temperature: Continuous operation up to 85°C with appropriate transmitter configuration-34-; standard range is 0°C to 100°C-1.
Pressure Rating: Maximum 10 bar continuous (1.0 MPa) with standard glass construction-; high‑pressure variants support up to 68 bar for specialized applications-34.
Model Code Breakdown: K9142TN
Understanding Yokogawa‘s naming convention helps in selecting the correct electrode and compatible accessories. The code K9142TN is interpreted as follows:
| Position | Code | Meaning |
| 1 | K9 | Series identifier — glass pH electrode family for industrial process measurement |
| 2 | 142 | Product variant within the K9 series; specifies sensing element geometry, glass composition, and reference system configuration |
| 3 | T | Reference junction type — ceramic porous junction for general‑purpose industrial use |
| 3 | N | Internal electrolyte type — KCl gel‑filled / non‑refillable design |
The complete model number is K9142TN with no additional suffix characters.
Replacement and accessory part numbers
| Description | Part Number |
| Glass electrode assembly | K9142TN |
| O‑ring, 6 mm ID × 9 mm OD | K9142QR |
| O‑ring, 9 mm ID × 12 mm OD | K9142QS |
| Junction assembly (for pure water) | K9142TK |
| KCl filling tube, 3 m length | K9142PF |
| KCl filling tube, 5 m length | K9142PG |
| KCl filling tube, 10 m length | K9142NJ |
| KCl filling tube, 15 m length | K9142NK |
| KCl filling tube, 20 m length | K9142NL |
| Cap assembly | K9142EJ |
| Bottle for general use (250 mL) | K9084KQ |
| Connector assembly (general use) | K9084CG |
| Holder assembly | K9142VE |
Source reference: YOKOGAWA PH8EHP parts list manual-11.
Complementary consumables and buffers:
| Item | Part Number | Description |
| KCl solution (3.3 M) | K9084LP | 6 × 250 mL polypropylene bottles |
| Buffer solution pH 4 | K9084LM | 6 × 250 mL polypropylene bottles |
| Buffer solution pH 7 | K9084LN | 6 × 250 mL polypropylene bottles |
| Buffer reagent pH 4 | K9020XA | 12 packets, each makes 500 mL solution |
| Buffer reagent pH 7 | K9020XB | 12 packets, each makes 500 mL solution |
| Buffer reagent pH 9 | K9020XC | 12 packets, each makes 500 mL solution |
| KCl reagent (refillable type) | K9020XU | 8 packets, each makes 250 mL solution |
| KCl reagent (diffusion type) | K9142TT | 2 packets including syringe |
Cable part numbers for PH200 / PH400 series transmitters:
| Cable Length | Part Number (HA405/DPA405/HF405) | Part Number (DPAS405) |
| 1 m | K9148KE | K9148RA |
| 3 m | K9148KF | K9148RB |
| 5 m | K9148KG | K9148RC |
| 10 m | K9148KH | K9148RD |
| 15 m | K9148KJ | K9148RE |
| 20 m | K9148KK | K9148RF |
Source reference: YOKOGAWA consumables parts manual-12.
Engineering Features
Low‑impedance glass membrane
The K9142TN incorporates a low‑impedance glass formulation that accelerates the development of a stable measurement potential. This design directly contributes to the sensor‘s ≤2‑second response time, enabling real‑time pH control in processes with rapid composition changes-6.
Double‑junction reference protection
Contamination of the reference electrode is a leading cause of pH measurement drift. The sensor’s double‑junction architecture places an additional electrolyte chamber between the internal Ag/AgCl reference element and the process liquid. This barrier prevents poisoning ions — such as sulfides, proteins, or heavy metals — from reaching the reference element, extending the electrode’s useful life in challenging media-2.
Integrated temperature compensation (ATC)
The K9142TN is equipped with an internal temperature sensing element. When connected to a compatible Yokogawa transmitter equipped with automatic temperature compensation (e.g., PH400G, FLXA21), the system adjusts measured pH values in real time for temperature effects. This feature eliminates manual compensation calculations and maintains accuracy across varying process temperatures from 0°C to 100°C-6.
Anti‑fouling geometry
In wastewater and slurry applications, suspended solids and biofilms tend to accumulate on sensor surfaces, slowing response and causing measurement errors. The K9142TN‘s tip geometry reduces particle adhesion, while the smooth glass surface resists biological growth, lowering cleaning frequency-6.
Material Compatibility
| Material | Component | Chemical Resistance |
| High borosilicate glass | Sensing membrane | Excellent against most mineral acids, organic solvents, and neutral salts |
| Corona‑treated glass | External housing | Enhanced surface hardness; resists scratching and chemical etching |
| PTFE / polymer | Junction element | Inert against strong acids, alkalis, and oxidizing agents |
| Ag/AgCl | Reference element | Stable in KCl electrolyte; avoid sulfides and cyanides |
| PVC sheath (optional) | Cable covering | Resists dilute acids, alkalis, and oils |
Not recommended for:
Hydrofluoric acid (HF) — any concentration. HF etches glass and destroys the sensing membrane.
Concentrated strong alkalis above pH 12.5 — accelerated glass corrosion reduces electrode life.
Anhydrous solvents — reference junction dehydration causes failure.
High‑velocity abrasive slurries — physical erosion of glass membrane.
Installation and Process Connections
The K9142TN supports three primary installation configurations, offering flexibility for different process vessel and piping layouts-6.
Immersion mounting: Insert the electrode directly into open tanks, basins, or sumps using a stainless steel immersion holder. Typical for wastewater equalization tanks, neutralization basins, and storage vessels.
Flow‑through mounting: Install the electrode in a flow cell assembly mounted to a process pipe. This configuration maintains consistent flow velocity across the sensing surface, reducing fouling. Ideal for clean water applications and low‑solids streams.
Flange mounting: Attach the electrode to a process vessel via a flanged adaptor. Suitable for pressurized reactors and high‑temperature autoclaves.
The standard connection thread is M20 x 1.5 female; an optional 1/2 NPT adaptor is available for North American installations-1. The electrode mounts in any orientation, though vertical mounting with the sensing tip pointing downward minimizes bubble entrapment.
Cable and Electrical Interface
The supplied cable is 1 meter in length as standard, extending to 3 m, 5 m, or 10 m by special order-6. The cable features:
Coaxial construction with a low‑noise polyethylene dielectric
Molded BNC connector for secure attachment to the transmitter
Shielded design to reject electromagnetic interference from nearby variable‑frequency drives or power cables-6
Optional PVC or Teflon outer sheath for chemical resistance
Maximum cable extension — for installations beyond 10 m, Yokogawa provides extension cables and junction boxes. Total conductor length should not exceed 20 m to maintain signal integrity. Where longer runs are unavoidable, employ a preamplifier mounted near the electrode to convert the high‑impedance pH signal into a low‑impedance current signal.
Electrical connection procedure:
Inspect the BNC connector for damage or contamination.
Insert the connector into the pH/mV input jack on the transmitter.
Rotate clockwise until it locks in place.
Avoid pulling or twisting the cable near the connector to prevent internal wire breaks.
Environmental Ratings
| Parameter | Rating |
| Ingress protection (sensor body) | IP67 — dust‑tight; protected against temporary immersion (up to 1 m depth for 30 minutes) |
| Relative humidity (non‑condensing) | ≤95% |
| Vibration resistance | 2 g peak, 10–150 Hz, per IEC 60068‑2‑6 |
| Shock resistance | 30 g, 11 ms half‑sine, per IEC 60068‑2‑27 |
| Altitude | Up to 2000 m above sea level |
The IP67 rating applies to the electrode body and connector when properly assembled. The wet side (glass membrane) remains exposed to the process liquid by design — this opening is not part of the IP rating. Install the sensor in locations protected from direct UV exposure, as prolonged sunlight degrades polymer cable sheathing over time.
Calibration and Maintenance
Calibration procedure
Yokogawa recommends two‑point calibration for general‑purpose use and three‑point calibration for critical applications. Use fresh buffer solutions at temperatures equal to the process temperature (±2°C).
Rinse the electrode with deionized water.
Immerse the sensing tip in pH 7.00 buffer (first calibration point).
Wait for reading stabilization (30–60 seconds depending on transmitter).
Initiate calibration at the transmitter.
Rinse again with deionized water.
Immerse in pH 4.01 buffer (acidic calibration point) or pH 9.18 buffer (alkaline calibration point).
Wait for stabilization and complete calibration.
Calibration frequency:
Clean water applications: every 30 days
Wastewater / process water: every 7–14 days
Chemical reactor monitoring: before each batch run
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